The announcement at 0300 on 19 February on myRoyalMail was for the Chinese New Year and included:
A special postmark will also appear today on all stamped UK and international mail.
It will read “Happy Chinese New Year 2015” and will feature a translation in Mandarin Chinese.
Sadly this was too late for collectors to post letters to get the postmark. Two versions exist, shown here from machine 1 at Medway Mail Centre (iLSM) and Lancashire and South Lakes (IMP):
I was told that a series of 8 slogans would be in use in conjunction with the Inventive Britain stamps. So far the only ones seen have celebrated Percy Shaw and his Catseyes.
Again, myRoyalMail indicates that there will be special postmarks over this week and next and Royal Mail van displays. This announcement was also at 0300 on 19 February, so too late to get a first day cover with the slogan unless you were fortunate enough to see the announcement.
Update from Press Release:
In addition to the stamps, Royal Mail will also be issuing special ‘Inventive Britain’ postmarks across the country from 20-28 February. Post across the country will (except Sunday) will be stamped with a message dedicated to one of the inventions.
Also, in locations where there are strong links to the inventors, Royal Mail vans will feature an image of the relevant stamp from the ‘Inventive Britain’ issue. They are; Halifax; Epsom; Sheffield; Edinburgh; Cirencester; Dumfries; Docklands and Mortlake.
Inventive Britain Stamps, Catseyes, Percy Shaw.
Lancashire and South Lakes on the Catseyes stamp, a first day cover:
and a day early from machine 6 at Medway MC (18 February):
Thanks to John C, John E and Bob M for alerting me to these. More examples will be shown on the Stampboards Forum for inclusion in the British Postmarks Database - an excellent searchable resource.
Further Inventive Britain postmarks:
Stainless Steel, Harry Brearley - Mount Pleasant (?) 19-02-2015
DNA Sequencing, Frederick Sanger - Glasgow 21-02-2015 and Bristol 21.02.15
Fibre Optics, Charles Kao + George Hockham - Greenford/Windsor 23.02.15, and Swindon 23-02-2015
Carbon Fibre,William Watt - Bristol 24.02.15 and Swindon 24-02-2015
i-Limb, David Gow - Manchester Mail Centre 25.02.15
Colossus, Tommy Flowers - SE Wales 26.02.15
World Wide Web, Tim Berners-Lee - SE Wales 27.02.15
More to come - please continue sending them - and thanks to Bob, Robert, John E, John G and another John E! And peterh on Stampboards.